The major science objective of the Spacelab-3 mission was to perform engineering tests on two new facilities: The rodent animal holding facility and the primate animal holding facility. In addition, scientists observed the animals to obtain firsthand knowledge of the effects of launch and reentry stresses and behavior. The need for suitable animal housing to support research in space led to the development of the Research Animal Holding Facility at the Ames Research Center. Scientists often study animals to find clues to human physiology and behavior. Rats, insects, and microorganisms had already been studied aboard the Shuttle on previous missions. On Spacelab-3, scientists had a chance to observe a large number of animals living in space in a specially designed and independently controlled housing facility. This photograph shows an astronaut tending the the rodent animal holding facility inside the module during this mission. Spacelab-3 (STS-51B) was launched on April 29, 1985 aboard the Space Shuttle Orbiter Challenger. The Marshall Space Flight Center had managing responsibilities for the Spacelab missions.